1. Field of the Invention
The present invention relates to an oxidation catalyst useful for promoting the selective oxidation of unsaturated hydrocarbons, such as olefins, in the presence of carbon monoxide, and to a method of using the catalyst to selectively oxidize such hydrocarbons in the presence of carbon monoxide.
The selective catalytic oxidation of unsaturated hydrocarbons in the presence of carbon monoxide is useful, for example, in treating carbon monoxide-containing gas streams to remove residual unsaturated hydrocarbons, in monitoring the concentration of combustible gases in a given environment, and in gauging the performance of catalysts used to treat exhaust or other waste gas streams, as described below.
2. Related Art
The prior art is aware of the use of vanadium phosphate catalysts for partial oxidation of C.sub.4 hydrocarbons, as indicated in an article by V. A. Zazhigalo, of the Inst. Fiz. Khim., Kiev, Ukraine, Katal. Katal. (1992), 28, 3-19.
The use of catalytic metals including alkali metals, alkaline earth metals, rare earth metals and noble metals on porous supports containing zirconium phosphate is known for the treatment of automotive exhaust gas, as shown by Japanese Patent Publication JP 08281116 A2, filed by Toyota Motor Company, Ltd. (Shinji Tsuji; Mikio Murachi).
The art also shows an awareness of the catalysis of oxidative dehydrogenation of isobutane by lanthanum phosphate and cerium phosphate, as shown by the article Role of Acidic Sites on Metal Phosphates in the Catalytic Oxidation of Isobutane by Y. Takita, K. Kurosaki, T. Ito, Y. Mizuhara and T. Ishihara (Stud. Surf. Sci. Catal., 1994).